The aim of this report is to examine the function of the headlamp washer and wiper on vehicles in traffic. Equipment for the measurement of dirt deposits on vehicles in traffic has been developed. Dirt deposits on headlamp were measured on a number of cars stopped by the police or when entering a petrol station. After measurement, headlamps were cleaned by using the headlamp washer and wiper and a new measurement was carried out. Finally, the headlamps were carefully cleaned by hand and a final measurement was carried out. On the same occasion, drivers were asked about their opinions concerning the headlamp washer and wiper. The physical measurements showed no significant differences of cleaning effects as regards car model or mileage. There are, however, differences between various types of washers where the type furnished with mechanical wipers showed a better result than high-pressure cleaning. Furthermore, cars where automatic headlamp cleaning was combined with the windscreen washer showed a better result than vehicles having a separate function for headlamp cleaning. Driver interviews showed that the majority (77%) considered their headlamp washers to be effective and an even greater majority (94%) considered headlamp washers essential equipment. (A)
Samenvatting